Patents Assigned to Northwest Tech Group Inc.
  • Patent number: 5771970
    Abstract: A tubing tightener which is readily adaptable to either clockwise or anti-clockwise rotational setting operation and which uses a series of drag slips having integral drag and slip surface regions. The drag surface regions are substantially smooth and are advanced into contact with a wellbore with the slip surface regions retracted, when the tightener is in its unlocked orientation. The slip surface regions are serrated to provide a positive engagement with the wellbore and are advanced into engagement with the wellbore with the drag surface regions retracted, when the tightener is in its locked orientation. The drag slips are caused to rock about a point of contact between the drag slip surfaces and the wellbore, located intermediate the drag and slip surface regions, in order to advance the appropriate surface region of each drag slip into engagement with the wellbore. The invention provides for a compact, lightweight construction with improved reliability and increased bypass around the tightener.
    Type: Grant
    Filed: July 2, 1996
    Date of Patent: June 30, 1998
    Assignee: Northwest Tech Group Inc.
    Inventor: William Jani
  • Patent number: 5623991
    Abstract: A tubing tightener which is readily adaptable to either clockwise or anti-clockwise rotational setting operation and which uses a series of drag slips having integral drag and slip surface regions. The drag surface regions are substantially smooth and are advanced into contact with a wellbore with the slip surface regions retracted, when the tightener is in its unlocked orientation. The slip surface regions are serrated to provide a positive engagement with the wellbore and are advanced into engagement with the wellbore with the drag surface regions retracted, when the tightener is in its locked orientation. The drag slips are caused to rock about a point of contact between the drag slip surfaces and the wellbore, located intermediate the drag and slip surface regions, in order to advance the appropriate surface region of each drag slip into engagement with the wellbore. The invention provides for a compact, lightweight construction with improved reliability and increased bypass around the tightener.
    Type: Grant
    Filed: December 6, 1995
    Date of Patent: April 29, 1997
    Assignee: Northwest Tech Group Inc.
    Inventor: William Jani